Automatic dock wheel chock for trailers



United States Patent 1,922,554 8/l933 McCosh [72] Inventor Frederick G.Noah I FOREIGN PATENTS 1022 SlvII C k R a Grants PISS, l,l2l .937 III962 Germany... 188/32 Oregon 97526 [2] 1 Appl 798.875 PramaryExaminer-George A. Halvosa [22] Filed Fem 13, 1969 Attorney-Clarence A.OBnen & Harvey B. Jacobson [45] Patented Nov. 24, 1970 [54] AUTOMATICDOCK WHEEL CHOCK FOR TRAILERS 6 Claims, 4 Drawing Figs.

[52] US. Cl. 188/32 [51] Int. Cl. B60t 3/00 [50] Field of Search l88/4A,32; 105/368; 248/1 19 [56] References Cited UNITED STATES PATENTS1,082,807 l2/l9l3 l-lolworthy 188/32 l. 88/324X ABSTRACT: A portableself-contained wheel actuated trailer chucking device characterized, bya channel-type base, a rocker shaft and a wheel seating and cradlingplate perched intermediate its ends atop the rocker shaft. When thetrailer wheel rides over and is nested in the concave seating portion,the rearward half-portion of the plate tilts down and the forwardhalf-portion is elevatedand blocks retrograde movement of the captivetrailer wheel. A pivoted retainer leg drops automatically behind a limitstop block and props the plate up. This plate stays put untilintentionally freed by a manually controllable leg tripping latch.

Piztnted Nov. 24, 1970 HHHHI W [1111 11 IIIII Frederick 6. NoahINVIfN'I'OK.

and

Allan AUTOMATIC DOCK WHEEL CHOCK FOR TRAILERS This invention relates toa portable self-contained trailer wheel positioning and blocking deviceor chock, more particu- -larly, a uniquely constructed self-settingchock which lends itself to feasible and reliable use when it isproperly located on a solid foundation or surface near the marginal edgeof a loading and unloading elevated platform or dock and which featureshis assistant may not carry out his duty of placing chocking blocks infront of the trailer wheels. Then, too, it is not unusual for air brakesto leak and fail to perform their intended function. Confronted withsuch difficulties it-isthe object of the present invention to provide asimple, practical and assuredly reliable device which will effectuallycope with and solve the overall problem .and will well serve thepurposes for which it has been devised.

In addition to the above broadly stated conditions it is a matter ofsignificanceto take into account the fact that a heavy forklift whenbacking out of the trailer tends to forcibly push the bed of the traileraway from the edge of the dock or platform and, as experience has shown,the spacethen existing between the trailer and the dock is often suchthat the forklift and seated operator can crash down to the ground andbring about every varying difficulties and injury to the operator. Itfollows that a primary purpose of the present invention is to preventretrograde movement of the trailer wheels and to reliably prevent thetrailer from accidentally shifting away from the dock. To the endsdesired, the invention is such in construction and capability that itconstitutes a safeguarding trailer anchoring and blocking device.

When two of the devices are .pared and properly located relative to eachother, the dock and the trailer, the likelihood leg. The leg is uniquein that it is provided on its median underside with a complementallatch, said latch being hingedly connected at its upper end to the legand having its lower end free, said lower end being so constructed andarranged that it can be manually engaged with a lug or detent on theunderneath side of the plate whereby it is thus necessary for thedriver, or other user, to intentionally bring the latch into play and tomove the leg to an out-of-the-way position when the trailer isintentionally moved out and away from the dock.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part thereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is'a v'iewin perspective of a wheel chock for trailersconstructed in accordance with the principles of the invention showingthe component parts in the initial cocked or ready-touse position andrelationship.

FIG. 2 isa longitudinal sectional view on a slightly enlarged scaletaken approximately on the plane of the section line 2-2 that thetrailer wouldaccidentally' displace itself from its chocked position,because of failure of the air brakesto' hold, is reduced toapracticalminimum. With this invention in use there is minimal chancethata driver would forget to block the wheels for the reasonthat thechocking and blocking result is achieved automatically, that is, whenthe trailer wheels have been properly lined upwith and guidingly backedover the self-setting wheel seating and cradling plates. It is also amatter of importance to take under consideration the fact that theinventionis a time andlabor saving device and includes a novel pivotallymounted latch which must be released manually. Accordingly, there islittle or 'no chance of the driver pulling out while'a forklift isoperating in and out of the rearward loading and unloading end ofthetrailer.

' Briefly, the wheel chocking device herein disclosed is characterizedby a portable elongated base, preferably a base which is channel-shapedin cross section with the result that the open ended channel provides awheel guiding track. The

' flanges forming the side walls of the channel are providedintermediate the rearward. and forward ends of the track with atransversely disposed rocker shaft. This rocker shaft has its headed orpeened ends rotatable in bearing holes provided therefor in theassociated flanges. The wheel seating and of FIG. 1 looking in thedirection of the arrows.

FIG. 3 is a view similar to and based on FIG. 2 and showing the wheelseating and cradling plate in its locked position.

And FIG. 4 is a view at right angles to FIGS. 2 and 3 takenapproximately on the plane of the vertical line 4-4 of FIG. 3.

The aforementioned base is denoted by the numeral 6 and is of elongatedform, is rigid in construction, made from suitable reliable strongmaterial and of the shape and dimension suggested in the views of thedrawing. More specifically, this base is in the form of an open endedchannel. Stated otherwise, it is channel-shaped in cross section andcomprises a flat web or bottom 8 whose rearward end is denoted by thenumeral 10. In actual practice this is the end of the channel which islocated adjacent or proximal to the edge of the elevated platform ordock (not shown). The opposite or forward end is denoted at 12 The termsrearward" and forward are used here in relation to the forward andrearward end portions of the trailer (also not shown). The spacedparallel duplicate upstanding flanges, which constitute the side wallsof the channel, are denoted at 14. Intermediate portions of the flangesbetween the ends 10 and 12 are provided with oppositely aligned holeswhich constitute bearings 16 for end portions of a horizontal transverserocker shaft 18. This shaft spans the spacebetween the flanges 14 andhas headed end portions 20 held in place in the manner shown. Thisrocker shaft provides support means for the longitudinally bowed wheelseating and cradling member, more specifically, the elongated arcuatelybowed plate 22. A median portion 24 of the plate is perched and fixedatop the rocker shaft 18 thus providing a half-portion 26 to the rightand asimilar half-portion 28 to the'left of the rocker shaft. Theforward end portion of the plate is provided with suitably bent andspaced knuckles 30 which are aligned with cooperating knuckles 32carried by an end of a plate-type leg 34. These knuckles serve toaccommodate a cradling member, more specifically an arcuately bowedplate,

has a median portion perched and fixed atop the shaft with the resultthat the half-portions are properly oriented'and balanced. The thusmounted plate is load-responsive and is capable of being shifted from aninactive chocked initial position to a subsequent wheel-chocking trailerretaining position. Elevating and retaining means is carried by theforward end of the plate and is preferably in the form of a properlyproportioned leg. The upper end of the leg is pivotally joined to theforward end of the plate and the lower end is free and is capable ofautomatically riding over and dropping behind an abutment or block whichfunctions as a limit stop shoulder for the pintle 36 thusinterconnecting the leg 34 with the rocker or plate 22.

When the device is in its initial ready-to-use or cocked position, theplate 22 and the leg 34assume the relationship illustrated in FIG; 1.

In order to achieve the automatic blocking and chocking result desiredand illustrated in full lines in FIG. 3, it will be' noted that the leg34-constitutes a prop with the result that the free lower end portion 38assumes the upwardly and rearwardly inclined position also shown in FIG.3, For best results, it has been found advisable to employ a simpleabutment, more specif callha transverse block 40 which is welded orotherwise secured in. place as at 42. The right hand or rearwardedgeportion 43 of the block constitutes a limit stop shoulder and when theleg is in the elevating position shown in FIG. 3 it is engaged with theshoulder 43. The safety aspect of the overall concept is aptly achievedby employing an auxiliary leg which is here referred to as a latch 44and which is proportional in size and shape and has one end portion.provided with pintles hingedly mounted in attaching ears 46 on theunderneath side of the median part of the leg 34. The free end of thislatch, that is the end denoted at 48 is releasably engageable with a lug50 mounted on the underneath side of the plate 22. This latch is shownin one position in FIG. 2, and in a second position in H0. 3. These maybe considered as the ineffective positions of the latch. When the latchis brought into play it is manually lifted up from the full lineposition shown in F l6. 3 to the dotted line' position whereupon the end48 is positioned against the detent or keeper 50 during which time theleg 34 is then held in an up and out-of-the-way position as shown inphantom lines.

It will be evident from the.views of the drawing andthe description thatthe chock has been devised and perfected with the idea in mind ofpreventing a trailer from accidentally moving away from the dock withwhich it is cooperable. The trailer, when backing over the chock movesthe tiltable and cradling and wheel seating plate 22 into the lockedposition shown in will not 3. The trailer when backing over the chockmoves the parts into this desirable locked position and the parts willnot unlock until the driver of the truck gets out and manipulates thelatch means 44 to achieve the released position shown in phantom linesin FIG. 3. The invention is not intended to position the trailer in anyparticular way but presents any accidental movement of the trailer whileforklifts (not shown) are operating in and out of the trailer. When thechock has been relcased'the action of the trailer which is being pulledoff the chock automatically sets it so that the next trailer that backsover it is then locked against the dock.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

lclaim:

1. For use when temporarily parking a tractor drawn .wheeled traileradjacent the platform of a loading and unloading dock, a wheel chockingdevice comprising, in combination, an elongated base adapted to beplaced in a ready-to-use position atop the parking surface, a one-piecewheel seating and cradling member of a length less than and aligned withand pivotally and rockably mounted intermediate its ends atop said baseintermediate its respective forward and rearward ends, said member beingwheel actuated and load responsive and automatically shiftable from aninactive cocked position substantially within the confines of said baseto a wheelchocking trailer retaining position, and elevating andretaining means carried by said member and automatically but releasablyengageable with an abutment which is fixedly mounted atop said base,said base being channel-shaped, the channel thereof providing anopen-ended wheel guiding and positioning track and embodying a whollyflat horizontal web interconnecting a pair of relatively shortupstanding vertical wheel confining and guiding flanges of equal height,said abutment comprising a block fixed atop said web and extendingtransversely across the top surface of the web and coacting with saidflanges and an edge thereof providing a limit stop shoulder for saidelevating and retaining means, said wheel seating and cradling membercomprising an arcuately bowed rigid plate the arcuate curvature of whichis conformable to the curvature of that portion of the tire which isnested and with the limit stop shoulder when the trailer wheel is nestedand cradled in the seating and chocking plate, and a manually actuableand controllable leg tripping latch having one end pivotally joined to amedian portion of said leg and a free end portion which is adapted to bereleasably engaged with a detent therefor which is fixed on a coactingunderneath surface of said plate in a manner to set the leg in anelevated out-of- .the-way position.

3. An automatic trailer wheel actuated chocking and docking devicecomprising a portable elongated tracklike base channel-shaped in crosssection, the channel of said base being open at its forward and rearwardends and embodying a flat horizontal web connecting a pair of relativelyshort upstanding spaced parallel wheel confining and guiding flanges. arigid one-piece elongated arcuately bowed wheel seating and cradlingplate of a length less than the length of and spaced within the limitsof said base, the arcuate curvature of said plate being conformable withthe curvature of the tread portion of the tire which is adapted to nestand seat itself conformingly atop said plate, a rocker shaft extendingtransversely across a median-portion of the channel and having endportions journaled for angular rotation in bearing holes providedtherefor in the respectively cooperable flanges, a median portion oftheunderneath convex surface of said plate being fixed atop and rockable inunison with said shaft, the respective half-portions of said plateextending forwardly and rearwardly, respectively, of said rocker shaftand being tiltably load-responsive when the wheel is seated in apredetermined manner atop the concave surface portion of said plate, anabutment block fixed atop a forward end portion of said web andproviding a limit stop shoulder, and a rigid depending plate-elevatingand propping leg having an upper end hingedly mounted on a cooperatingend of said plate and a free lower end which is releasably engageablewith said limit stop shoulder.

4. The trailer wheel chocking device defined in and according to claim3, and wherein said plate provided on an underneath surface with a fixeddepending keeper-type lug, said lug being spaced from cooperating endand providing a detent, and a manually actuable and controllable legtripping safety latch having an upper end pivotally joined to a medianportion of said leg and a lower free end portion which is adapted to bereleasably engaged with said detent whenever necessary or desired,whereby to position and hold the-leg in an out-of-theway position. v

5. The trailer wheel chocking device defined in and according to claim4, and wherein said latch is of a transverse corsssectional dimensiongreater than the distance between the pivot point of said latch andlocale. of said detent that, when in use, it elevates and maintains saidleg in said out-of-the-way position until said latch is manuallyreleased from said detent.

6. The trailer wheel chocking device defined in and according to claim5, and wherein said leg is of a transverse cross-sectional dimensiongreater than the distance between the pivot point and the limit stopshoulder when the plate is in a normal ready-to-function position.

